1. Field of the Invention
The present invention relates to a surface texture measuring machine for measuring surface roughness, waviness, profile etc., an leveling device for the surface texture measuring machine and an orientation-adjusting method of a workpiece disposed on the surface texture measuring machine, which is specifically used for correcting relative inclination between the workpiece and measurement direction of a sensor before actual measurement, the workpiece being convex or concave and having edge line such as cylindrical shape and conic shape.
2. Description of Related Art
Conventionally, a form measuring instrument for measuring surface roughness or profile of a workpiece having cylindrical shape, conic shape etc. is known. FIGS. 17 and 18 show example workpieces of the related art (Japanese Patent Laid-Open Publication No. Hei 8-29153 to Fukuda).
The form measuring instrument has a drive means for driving a workpiece relative to a sensor, where an orientation of the workpiece rested on a stage is automatically corrected to a reference orientation (orientation in conducting actual measurement) in advance to the actual measurement, thus defining a position to center or level the workpiece.
However, the above-described form-measuring instrument requires a drive sources such as a motor for moving the stage in X-axis direction (measurement direction), Y-axis direction.(a direction orthogonal with the measurement direction on a horizontal plane) and Z-axis direction (a direction orthogonal with the measurement direction in a perpendicular plane). As a result, a space for attaching a plurality of motors is required, thus complicating the structure of the device, so that the size of the measuring machine is increased.
Further, since the measuring machine requires the plurality of motor, vibrations from respective motors can be overlapped to generate great vibration, thus impairing highly accurate measurement. For preventing the vibration, rigidity of base such as the stage has to be increased, thus further increasing the size of the device. Moreover, since the device requires the plurality of motor, the device can be expensive.
An object of the present invention is to provide a surface texture measuring machine, an leveling device for the surface texture measuring machine and an orientation-adjusting method of workpiece of the surface texture measuring machine, where the orientation of the workpiece can be easily adjusted without impairing operability, the size and cost of the device can be reduced and highly accurate measurement is possible.
In the present invention, the above object is achieved by manually moving a workpiece orientation adjustment stage in accordance with a calculated orientation correction amount of the workpiece to adjust the orientation of the workpiece, thus accurately scanning the texture of the workpiece by the surface texture measuring machine.
More specifically, a surface texture measuring machine according to the present invention is for measuring a surface texture of a workpiece held on a workpiece orientation adjustment stage, the workpiece having an edge line and being movable in a measurement direction (X-axis direction) and in a direction (Y-axis direction) orthogonal with the X-axis direction within a horizontal plane and rotatable in a X-Y plane, the workpiece being capable of seesawing in a direction (Z-axis direction) orthogonal with the X-axis direction within a perpendicular plane, the surface texture of the workpiece being scanned by a sensor movable in the X-axis direction after adjusting orientation of the workpiece, the surface texture measuring machine is characterized in having: a measurement controller for adjusting the orientation of the workpiece; and a measurement means being controlled by the measurement controller, the measurement controller comprising: a surface texture measurement controller for measuring the surface texture of the workpiece; a X-axis coordinates input means for inputting X-axis coordinates at a measurement start point and a measurement end point in adjusting the orientation of the workpiece; a Y-axis coordinates input means for inputting Y-axis coordinates at a measurement start point and a measurement end point in adjusting the orientation of the workpiece; a swivel correction angle calculation means for calculating a swivel inclination angle (an inclination angle within the X-Y plane relative to X-axis) and a swivel correction angle from the X-axis coordinates inputted by the X-axis coordinates input means and the Y-axis coordinates inputted by the Y-axis coordinate input means; and a swivel correction angle display for displaying the swivel correction angle calculated by the swivel correction angle calculation means, the measurement means comprising: a Y-axis adjustment means for adjusting orientation of the workpiece by manually displacing the workpiece in the Y-axis direction in accordance with the swivel correction angle displayed on the swivel correction angle display; and a swivel adjustment means for manually rotating the workpiece within the X-Y plane to adjust orientation thereof.
The workpiece having edge line includes workpiece having hog-backed shape, square-pillar shape such as triangular pillar and pentagonal pillar and pyramidal shape such as triangular pyramid and pentagonal pyramid as well as cylindrical shape (solid or hollow) and conic shape.
Further, as long as the workpiece is put on the workpiece orientation adjustment stage so that edge line thereof can be seen, other workpiece having square pillar shape such as rectangular pillar and hexagonal pillar, pyramidal shape such as square pyramid and hexagonal pyramid may be measured.
Further, the edge line may be curved (for instance, when the workpiece is curved cylindrical shape) and the edge line does not necessarily continue all the length over the workpiece as long as a certain amount of length is continued.
Further, adjustment of orientation refers to align the workpiece to a reference orientation in conducting the actual measurement, which is not restricted to one orientation per one workpiece but may be a plurality of orientation. For instance, when the workpiece is cylindrical, there can be a reference orientation adapted for measuring roughness and profile along axial direction of the cylinder and another reference orientation adapted for measuring roughness and profile along radial direction of the cylinder (a direction orthogonal with the axis thereof).
Further, as the stage means, a stage for the workpiece to be rested thereon, a V-block, a vice and a clip or a combination thereof can be used.
As the Y-axis adjustment means and the swivel adjustment means, micrometer head etc. with the correction amount being digitally displayed and having a knob thereon may preferably be used so that the workpiece can be manually moved in Y-axis direction and can be manually rotated on the X-Y thus adjusting with high accuracy. However, other arrangement is possible as long as the same effect can be obtained.
According to the present invention, the workpiece having the edge line is put on the workpiece orientation adjustment stage and the workpiece orientation adjustment stage and the sensor is relatively displaced to adjust the orientation of the workpiece into the reference orientation (an orientation during actual measurement). Subsequently, surface texture of the workpiece at the reference orientation is measured.
At this time, in order to adjust the orientation of the workpiece, the orientation of the workpiece is preliminarily measured at two points on the workpiece put on the workpiece orientation adjustment stage along measurement direction. Base on the measurement result of the preliminary measurement, an error of the orientation of the workpiece relative to the reference orientation is calculated by the swivel correction calculation means, and the operator manually operates the Y-axis adjustment means and the swivel adjustment means to correct the orientation of the workpiece into a reference orientation based on the value displayed on the swivel correction amount display.
Accordingly, in adjusting the orientation, the operator can adjust the orientation of the workpiece on the X-Y plane by operating the Y-axis adjustment means and the swivel adjustment means according to the correction amount calculated from the measurement start point and the measurement end point of the workpiece put on the workpiece orientation adjustment stage. Since it is necessary for the operator only to operate the respective adjustment means until the displayed correction amount is reached, operation can be facilitated and the orientation of the workpiece can be conducted with high accuracy without impairing operability.
Further, the respective adjustment means can be manually operated, drive means such as motor is not required. Accordingly, a space for attaching the motor is not necessary, thus simplifying the structure of the device and reducing the size and cost thereof.
In the surface texture measuring machine according to the present invention, the measurement controller may preferably further include: a Z-axis coordinates input means for inputting Z-axis coordinates of the workpiece at the measurement start point and the measurement end point in adjusting orientation of the workpiece; an inclination correction calculation means for calculating an inclination amount within a X-Z plane and an inclination correction amount from the X-axis coordinates and the Z-axis coordinates inputted by the Z-axis coordinates input means; and an inclination correction display for displaying inclination correction amount calculated by the inclination correction calculation means, and the measurement means may preferably further include an inclination adjustment means for manually displacing the workpiece in Z-axis direction in accordance with the inclination correction amount calculated by the inclination correction calculation means for adjusting orientation thereof.
The above Z-axis adjustment means may preferably be a micrometer head etc. with the correction amount being digitally displayed thereon and having a knob for facilitating manually moving the workpiece in Z-axis direction and enabling adjustment with high accuracy. However, other arrangement is possible as long as the same effect can be obtained.
According to the present invention, since the movement of the workpiece in Z-axis direction, i.e. inclination can be adjusted, the orientation within the X-Z plane can be adjusted with higher accuracy, thus enabling highly accurate actual measurement.
In the surface texture measuring machine, the Y-axis adjustment means, the swivel adjustment means and the inclination adjustment means respectively may preferably include a micrometer head.
The micrometer head may preferably include a display for digitally displaying the correction amount.
According to the present invention, since the orientation can be adjusted by operating the micrometer head, the orientation can be adjusted with high accuracy without impairing operability.
An orientation adjusting method of a workpiece according to the present invention uses a surface texture measuring machine, the workpiece having an edge line and being movable in a measurement direction (X-axis direction) and in a direction (Y-axis direction) orthogonal with the X-axis direction within a horizontal plane and rotatable in a X-Y plane, the workpiece being capable of seesawing in a direction (Z-axis direction) orthogonal with the X-axis direction within a perpendicular plane, the surface texture of the workpiece being scanned by a sensor movable in the X-axis direction after adjusting orientation of the workpiece. The orientation adjusting method is characterized by having the steps of: measuring positions of the workpiece relative to the sensor at a measuring start point and a measurement end point; calculating orientation of the workpiece from the positions to obtain an orientation correction angle; displaying or printing the orientation correction angle; and operating an adjustment means of the workpiece orientation adjustment stage to correct the orientation of the workpiece.
According to the present invention, the orientation of the workpiece can be adjusted by operating the Y-axis adjustment means and the swivel adjustment means in accordance with the correction amount calculated by the measurement start point and measurement end point of the workpiece put on the workpiece orientation adjustment stage. Since it is only necessary for the operator to operate the respective adjustment means until the displayed correction amount is reached, operation thereof can be facilitated and the orientation of the workpiece can be highly accurately adjusted without impairing operability.
Further, since the respective adjustment means can be manually operated, drive means such as motor is not required. Accordingly, a space for attaching the motor is not required, thus simplifying structure thereof and reducing size and the cost thereof.
In the orientation-adjusting method, the position of the workpiece at the measurement start point and the position of the workpiece at the measurement end point may preferably be detected as a maximum value or a minimum value of Z-axis coordinates within Y-Z plane.
According to the above arrangement, since the present invention can be applied to a workpiece having concave surface such as inner surface of a cylinder as well as outer surface of the cylinder, thus enlarging applicability of the present invention.
In the orientation-adjusting method according to the present invention, the orientation of the workpiece may preferably be conducted by rotating the workpiece on the X-Y plane relative to the sensor.
According to the present invention, since the orientation is adjusted based on the rotation within the X-Y plane, the workpiece can be aligned with the reference measurement direction only by a small angle of movement, so that the orientation can be adjusted immediately.
In the orientation-adjusting method according to the present invention, the orientation of the workpiece may preferably be adjusted by seesawing the workpiece on the X-Z plane relative to the sensor.
According to the present invention, since the orientation of the workpiece can be adjusted by seesawing the workpiece within X-Z plane, the workpiece can be aligned to a reference plane only by a small angle of tilting, thus enabling immediate orientation adjustment.
An leveling device according to the present invention is for a surface texture measuring machine having: a displacement detecting means movable in a measurement direction (X-axis direction) for measuring displacement on a surface of a workpiece; and a moving means for moving the displacement detecting means in the measurement direction to scan a displacement signal from the displacement detecting means, the surface texture measuring machine adjusting an amount of the workpiece relative to a base line as a movement locus of the displacement detecting means. The leveling device is characterized in having: a fulcrum during measurement and adjustment and a point of action working relative to the fulcrum; a manipulated valuable calculation means for scanning the surface of the workpiece by the displacement detecting means and for calculating a center locus of measurement data based on a displacement signal from the displacement detecting means to calculate a operation amount at the point of action relative to the fulcrum required for paralleling the center locus with the base line of the moving means; an output means for displaying, printing or outputting as data the operation amount; and an inclination adjustment means for manually adjusting inclination of a predetermined amount.
The above displacement detecting means may have any one of a contact type or a non-contact type displacement sensor as long as the sensor can measure the displacement (height) on the surface of the workpiece and can output a signal. Further, the inclination adjustment may preferably be a micrometer head including absolute micrometer head for manual accurate adjustment. However, other arrangement is possible as long as the same effect can be obtained by manual operation.
According to the present invention, the center locus of the measurement data obtained by scanning the surface of the workpiece is calculated by the operation amount calculation means. The inclination of the center locus is adjusted by the inclination adjustment means in accordance with the operation amount outputted by the output means to be parallel with the base line of the moving means. Accordingly, since the center locus of the measurement data is moved relative to the base line of the moving means to be parallel with each other and the inclination adjustment amount is given as an absolute quantity, so-called cosine error can be prevented to eliminate the inclination adjustment error, so that the orientation of the workpiece can be adjusted easily without impairing operability. Further, since the inclination can be manually adjusted without using a motor, the size and cost of the device can be reduced.
In the leveling device according to the present invention, the operation amount may preferably be calculated from an inclination reference position where an inclination line connecting the fulcrum and the point of action of the inclination adjustment means is parallel with the base line of the moving means.
According to the present invention, since the operation is conducted relative to the inclination adjustment reference position, so-called cosine error is unlikely to be caused and the inclination can be adjusted with one operation, thus facilitating the operation.
In the leveling device according to the present invention, the inclination adjustment means may preferably include a micrometer head.
The micrometer head constituting the inclination adjustment means includes an absolute micrometer head.
According to the present invention, the cost of the adjustment mechanism can be lowered, and when the absolute micrometer head is specifically used, the inclination can be accurately adjusted with small number of inclination adjustment operation.
In the leveling device according to the present invention, the operation amount includes operation amount at any two points on the inclination adjustment means conducting three-point support.
According to the present invention, since the inclination adjustment means can be independently operated at the two points, the inclination can be adjusted not only in X-axis direction but also in Y-axis (an axis orthogonal with X-axis direction on a horizontal plane) direction. Accordingly, the surface of the workpiece can be three-dimensionally measured, thus enlarging measurement range.
In the leveling device according to the present invention, any one of the workpiece and the moving means may preferably be provided.
According to the above arrangement, since the moving means is provided thereon, the inclination of the moving means can be adjusted. Accordingly, the inclination of the workpiece can be easily adjusted even when the size of the workpiece is large or when the workpiece is too heavy to put on the stage.